A126328 Rounded value of n!/(n(n+1)/2); A000142(n)/A000217(n).

1, 1, 1, 2, 8, 34, 180, 1120, 8064, 65978, 604800, 6141046, 68428800, 830269440, 10897286400, 153844043294, 2324754432000, 37440781904842, 640237370572800, 11585247657984000, 221172909834240000, 4442690623626907826

Offset

1,4

Comments

This is the value that comes up when (all positive integers n and below multiplied together) is divided by (all positive integers n and below added together). Some terms need to be rounded, but for some terms, n! is divisible by n(n+1)/2. See A060462 for these numbers.

Links

Table of n, a(n) for n=1..22.

Example

a(6) = 34 because 6! = 720 and 6(6+1)/2 = 21. 720/21 = 34.2857... rounded to 34.

Mathematica

Table[Round[n!/(n(n+1)/2)], {n, 22}] (* James C. McMahon, Dec 25 2024 *)

Crossrefs

Cf. A000142, A000217, A060462.

Cf. A061370. [From R. J. Mathar, Dec 13 2008]

Sequence in context: A030960 A121894 A061370 * A268558 A191569 A229812

Adjacent sequences: A126325 A126326 A126327 * A126329 A126330 A126331

Keyword

nonn

Author

Jonathan R. Love (japanada11(AT)yahoo.ca), Mar 09 2007

Status

approved